The country also has 402 kilometers (249 miles) of coastline on the Bight of Biafra, part of the Atlantic Ocean. The topography of Cameroon is varied, ranging from tropical rain forests in the south to mountainous highlands in some western central regions, and semi-arid savanna in the far north.
The Ionisphere bounces radio waves back to earth and regulates the amount of radiation that gets to the lower atmospheres. It all depends on the Sun's activity. The stratosphere is what actually protects us from the UV rays of the sun.
Waves that travel in the rocks below the surface of the earth are called body waves, and there are two types of body waves: primary, or P, waves, and secondary, or S, waves. The S waves, also known as shearing waves, cause the most damage during earthquake shaking, as they move the ground back and forth.